CVE-2023-52081
However, due to the use of late Unicode normalization of type NFKD, it is possible to bypass that validation and re-introduce all the characters in the regex `[-_ .]`.
Does this matter?
Lower severity and a low EPSS score (0.52%). Track it; it rarely justifies an emergency change on its own.
Description
ffcss is a CLI interface to apply and configure Firefox CSS themes. Prior to 0.2.0, the function `lookupPreprocess()` is meant to apply some transformations to a string by disabling characters in the regex `[-_ .]`. However, due to the use of late Unicode normalization of type NFKD, it is possible to bypass that validation and re-introduce all the characters in the regex `[-_ .]`. The `lookupPreprocess()` can be easily bypassed with equivalent Unicode characters like U+FE4D (﹍), which would result in the omitted U+005F (_), for instance. The `lookupPreprocess()` function is only ever used to search for themes loosely (case insensitively, while ignoring dashes, underscores and dots), so the actual security impact is classified as low. This vulnerability is fixed in 0.2.0. There are no known workarounds.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.52% probability · 43th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-74, CWE-176
- Affected
- ewen-lbh/firefox css
- Source
- security-advisories@github.com
References
- https://github.com/ewen-lbh/ffcss/commit/f9c491874b858a32fcae15045f169fd7d02f90dcPatch
- https://github.com/ewen-lbh/ffcss/security/advisories/GHSA-wpmx-564x-h2mhExploit, Vendor Advisory
- https://github.com/ewen-lbh/ffcss/commit/f9c491874b858a32fcae15045f169fd7d02f90dcPatch
- https://github.com/ewen-lbh/ffcss/security/advisories/GHSA-wpmx-564x-h2mhExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.